June 2, 2020 Zimmerman/Batchelor podcast
Embedded below the fold in two parts.
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Year: 2020
InSight mole team reports some digging success
Click to watch movie.
A new strategy devised in February to use the scoop on the Mars InSight lander to push down on the mole digging tool so that it could gain traction and dig downward has apparently had some success.
We started about seven centimetres above the surface on Sol 458 (11 March) and we are now at the surface with the scoop on Sol 536 (30 May 30), after six cycles of hammering over 11 weeks.
If you click on the image on the right you can see a movie assembled from images taken since February as they pushed down. The mole has clearly descended into the Martian soil about seven centimeters, or about three inches. The issue now, as shown in the movie, is that the mole is now deep enough that the scoop is pressed against the ground. It can’t really push down anymore on the mole, at least in this configuration.
They have the option of using the scoop’s tip to push farther into the ground, but that involves some risk. First they plan to let the mole continue to dig, without the scoop’s help, in the hope that it is now finally deep enough into the ground that the ground is finally able to provide the friction required to hold the mole in place. If this doesn’t work, they will then try using the scoop to fill the hole up to provide more friction.
If that doesn’t work, they will then try using the scoop tip to provide the added pressure.
All in all, it does appear there is now hope that the mole will eventually get the heat sensor for measuring the internal temperatue on Mars deep enough to do its primary mission. Stay tuned!
Rethinking the theories that explain some supernovae
The uncertainty of science: New data now suggests that the previous consensus among astronomers that type Ia supernovae were caused by the interaction of a large red giant star with a white dwarf might be wrong, and that instead the explosion might be triggered by two white dwarfs.
If this new origin theory turns out to be correct, then it might also throw a big wrench into the theory of dark energy.
The evidence that twin white dwarfs drive most, if not all, type Ia supernovae, which account for about 20% of the supernova blasts in the Milky Way, “is more and more overwhelming,” says Dan Maoz, director of Tel Aviv University’s Wise Observatory, which tracks fast-changing phenomena such as supernovae. He says the classic scenario of a white dwarf paired with a large star such as a red giant “doesn’t happen in nature, or quite rarely.”
Which picture prevails has impacts across astronomy: Type Ia supernovae play a vital role in cosmic chemical manufacturing, forging in their fireballs most of the iron and other metals that pervade the universe. The explosions also serve as “standard candles,” assumed to shine with a predictable brightness. Their brightness as seen from Earth provides a cosmic yardstick, used among other things to discover “dark energy,” the unknown force that is accelerating the expansion of the universe. If type Ia supernovae originate as paired white dwarfs, their brightness might not be as consistent as was thought—and they might be less reliable as standard candles.
If type Ia supernovae are not reliable standard candles, then the entire Nobel Prize results that discovered dark energy in the late 1990s are junk, the evidence used to discover it simply unreliable. Dark energy might simply not exist.
What galls me about this possibility is that it was always the case. The certainty in the 1990s about using type Ia supernovae as a standard candle to determine distance was entirely unjustified. Even now astronomers do not really know what causes these explosions. To even consider them to always exhibit the same energy release was just not reasonable.
And yet astronomers in the 1990s did, and thus they fostered the theory of dark energy upon us — that the universe’s expansion was accelerating over vast distances — while winning Nobel Prizes. They still might be right, and dark energy might exist, but it was never very certain, and still is not.
Much of the fault in this does not lie with the astronomers, but with the press, which always likes to sell new theories as a certainty, scoffing over the doubts and areas of ignorance that make the theories questionable. This is just one more example of this, of which I can cite many examples, the worst of all being the reporting about global warming.
Exoplanet in Earth-like orbit circling Sun-type star
Worlds without end: Astronomers have found evidence suggesting the existence of an exoplanet about twice as massive as the Earth and orbiting a solar-twin star in an orbit almost the same as the Earth’s.
The star, Kepler-160, is about 3,000 light years away, and had previously discovered to have two exoplanets.
“Our analysis suggests that Kepler-160 is orbited not by two but by a total of four planets,” Heller summarizes the new study. One of the two planets that Heller and his colleagues found is Kepler-160d, the previously suspected planet responsible for the distorted orbit of Kepler-160c. Kepler-160d does not show any transits in the light curve of the star and so it has been confirmed indirectly. The other planet, formally a planet candidate, is KOI-456.04, probably a transiting planet with a radius of 1.9 Earth radii and an orbital period of 378 days. Given its Sun-like host star, the very Earth-like orbital period results in a very Earth-like insolation from the star – both in terms of the amount of the light received and in terms of the light color. Light from Kepler-160 is visible light very much like sunlight. All things considered, KOI-456.04 sits in a region of the stellar habitable zone – the distance range around a star admitting liquid surface water on an Earth-like planet – that is comparable to the Earth’s position around the Sun.
“KOI-456.01 is relatively large compared to many other planets that are considered potentially habitable. But it’s the combination of this less-than-double the size of the Earth planet and its solar type host star that make it so special and familiar,” Heller clarifies. As a consequence, the surface conditions on KOI-456.04 could be similar to those known on Earth, provided its atmosphere is not too massive and non-Earth-like. The amount of light received from its host star is about 93 percent of the sunlight received on Earth. If KOI-456.04 has a mostly inert atmosphere with a mild Earth-like greenhouse effect, then its surface temperature would be +5 degrees Celsius on average, which is about ten degrees lower than the Earth’s mean global temperature.
These results have many uncertainties, so we should not be surprised if further research produces significant revisions in these conclusions. Nonetheless, the number of Earth-like planets orbiting Sun-like stars in orbits like the Earth’s continues to rise.
A detailed update on SpaceX’s Starlink satellite constellation
Link here. With yesterday’s launch, SpaceX now has put 420 satellites in orbit.
In a recent interview with Aviation Week, SpaceX President Gwynne Shotwell said that they should begin beta testing the network this year and would want to complete around 14 launches before publicly promoting Starlink service. That could allow service to begin as soon as early 2021 depending on how fast launches can be performed.
In a recent ITU filing, SpaceX laid out a very aggressive schedule for continuing the Starlink deployment, with 13 launches in the May to September time period. This schedule is likely to spread out a bit as they run into normal launch cadence issues such as weather, range coordination, booster recovery operations, and booster refurbishment.
The first launch in that group (June 3 in Florida) has been delayed nearly a month for the above reasons. Regardless of exactly how long those launches end up taking, Ms. Shotwell’s comments indicate SpaceX doesn’t think satellite production will be a gating factor for their deployments in the near future.
An interesting feature of the schedule is that after this frenzy of launches, there would be a gap with only one launch in four months, followed by a period of twice-monthly launches to finish out the initial 1584 satellite shell of the constellation. SpaceX may have options to make changes to the satellites during that pause in the deployments, such as adding the optical inter-satellite links that have been mentioned as debuting later in 2020.
The article then provides a great deal of information about the system’s design and status for beginning operations in the U.S. Well worth a close read.
ArianeGroup developing new rocket engine
Capitalism in space: The private company ArianeGroup has now gotten the okay from the European Space Agency (ESA) to begin full development of its new Prometheus rocket engine, intended to reduce costs 10x.
By applying a design-to-cost approach to manufacturing Prometheus, ESA aims to lower the cost of production by a factor of ten of the current main stage Ariane 5 Vulcain 2 engine. Features such as variable thrust, multiple ignitions, suitability for main and upper stage application, and minimised ground operations before and after flight also make Prometheus a highly flexible engine.
This Prometheus precursor runs on liquid oxygen–methane which brings high efficiency, allows standardisation and operational simplicity. Methane propellant is also widely available and easy to handle.
Essentially, ArianeGroup is going to try to build its own methane-powered rocket engine, having seen the success that SpaceX has so far had with its own Raptor methane engine. This also signals an increased recognition at ESA and ArianeGroup that their new Ariane-6 rocket, whose first launch is still about a year away, is not going to be competitive with SpaceX’s offerings, and needs to be upgraded or replaced.
The Ides Of March – Vehicle
An evening pause: Performed live 2014.
Hat tip Roland.
American Kristallnacht
It might have been an accident, or maybe it was because of the events of the past three months, but earlier this year I decided to finally read William Shirer’s masterpiece, The Rise and Fall of the Third Reich. Previously I had only read the first few chapters in order to learn something about Hitler’s background. Now it was time to read the whole book.
I am only halfway through it but no matter. Every page has sent terror through my soul, as it appears to not be a history of the 1930s foolishness and madness that allowed a megalomaniac to become the leader of a powerful nation, intent on conquering the world while committing genocide against millions, but a news report of modern America.
What we have seen for the past three months — accelerated to madness with riots this week — has been nothing more than a return to the Nazi tactics of the 1930s, with the only difference being that the targets have not been just Jews, but all private businesses as well as anyone who dares to oppose their wanton destruction. In fact, the use of rocks to break windows and loot businesses and attack and even kill their owners this week was so reminiscent of Kristallnacht that I find it more than horrifying. From the link:
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Live feed of tonight’s SpaceX Falcon 9 Starlink launch
UPDATE: A successfully launch, with a successful landing of the first stage, the fifth time this particular stage has completed a mission.
10 China
8 SpaceX
7 Russia
3 ULA
The U.S. now leads China 13 to 10 in the national rankings.
Original post:
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Since there was such a positive response to the embedded live feed of SpaceX’s first manned Dragon launch a few days go, I’ve decided to embed below the live feed of their next launch tonight of 60 Starlink satellites. The launch is set for 9:25 pm (Eastern), with the live feed starting fifteen minutes before that.
Enjoy. Watching that first stage land never gets old.
The coming death of America
I have been so appalled and horrified by the events of the past three months, culminating in the riots and brutal violence and looting this past week, that I have found myself unable to express myself. I stand for freedom, for justice, for equal protection under law, and for our Constitution and Bill of Rights, fundamental documents that more than any philosophical tract ever written outline the most just way to run a country.
That country however appears to be dying, fast. It strongly appears that a large plurality, maybe even a majority, no longer believes in these ideals. This fact has made me depressed beyond words.
The speech below by Tucker Carlson however does a very good job of summing things up, based on facts, while making it clear what we must do to change this madness. He pulls no punches. He attacks every politician from both parties who have stood by or even supported the rioting and the nullification of our most basic laws. He demands better from them, and he demands that we, the citizenry, demand it as well.
I beg my readers to watch it. Set the speed at 1.25 and you can see it faster.
I also pray that some of my readers, after watching it, will recognize how deadly the situation really is, far beyond rioting, and how necessary it is for us to require proper behavior from our leaders, without exception, based on law and justice. No more race-baiting. No more apologies for enforcing the law meant to protect the innocent. No more cowardice. If our political leaders can’t protect everyone, then they must be fired. All of them.
And if we, the American people, still fail to recognize how bad things are and refuse to do something about it, then my headline above will simply be an accurate prediction. I weep to think I might be right.
I must also add that to understand what I mean, you must watch Carlson’s speech first. Otherwise, you will be doing exactly what I rage against.
Forty Fingers – Bohemian Rhapsody
An evening pause: This is really badly filmed, with the camera constantly moving in a very distracting way, never stopping to actually let you watch them play. Very annoying.
However, the music is still magnificent, and the guitar arrangement is brilliant. Turn it on and listen as you do something else. You’ll enjoy it more.
Hat tip John Jossy.
The strange squashed ridges at the basement of Mars
Click for full image.
Cool image time! The photo on the right, cropped and reduced to post here, was taken by the high resolution camera on Mars Reconnaissance Orbiter (MRO) on April 9, 2020, and shows the very weird and very packed ridges and layers that are found routinely at the deepest part of Hellas Basin, what I have dubbed the basement of Mars.
Be sure to click on the image to see the full photograph. There’s lots more strangeness to see there. And be sure to read my post in the second link, which highlights a similarly strange set of packed ridges, and where I note:
This is the basement of Mars, what could be called its own Death Valley. The difference however is that unlike Death Valley, conditions here could be more amendable to life, as the lower elevation means the atmosphere is thicker.
The context map to the right shows Hellas, with the location of today’s image indicated by the white box, close to basin’s lowest point, more than five miles below the basin’s rim. Overall the Hellas Basin is about the size of the western United States, from the Mississippi River to the Pacific Ocean. It is believed that the entire basin was created by a single gigantic impact that occurred about four billion years ago when the solar system’s inner planets were undergoing what has been labeled the Late Heavy Bombardment.
The specific process that formed these ridges, dubbed honeycomb terrain by scientists, remains unknown however. There are of course theories, none of which are very convincing. Here’s mine, as outlined in the previous post:
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